11841981 has 4 divisors (see below), whose sum is σ = 15789312. Its totient is φ = 7894652.

The previous prime is 11841971. The next prime is 11842001. The reversal of 11841981 is 18914811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11841981 - 2⁶ = 11841917 is a prime.

It is a super-2 number, since 2×11841981² = 280465028008722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11841971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1973661 + ... + 1973666.

It is an arithmetic number, because the mean of its divisors is an integer number (3947328).

Almost surely, 2^11841981 is an apocalyptic number.

It is an amenable number.

11841981 is a deficient number, since it is larger than the sum of its proper divisors (3947331).

11841981 is an equidigital number, since it uses as much as digits as its factorization.

11841981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3947330.

The product of its digits is 2304, while the sum is 33.

The square root of 11841981 is about 3441.2179529928. The cubic root of 11841981 is about 227.9334793629.

The spelling of 11841981 in words is "eleven million, eight hundred forty-one thousand, nine hundred eighty-one".